A Privacy Policy Conflict Detection Method Based on Sub-graph Isomorphism

Privacy policy plays an important role in the collection and usage of privacy data. Compared with the access control policy, the privacy policy shows three characteristics: (1) the set of privacy policies can offer more semantics; (2) The privacy policy is created by the data owner, whereas the access control policy is created by the database manager; (3) they work in different ways, accurate matching for the privacy and sequence matching for the access control. All of the characteristics make the privacy policy more complex and much easier to produce conflicts. In order to give better solution for the conflicts, this paper proposes a method based on sub-graph isomorphic. This method models the privacy policy and each possible policy conflict pattern as a stratified-directed graph (SDG), and an algorithm is proposed to detect whether the SDG of a privacy conflict mode is isomorphic to that of privacy policies.